CN115160539A

CN115160539A - Process for preparing epoxy resin

Info

Publication number: CN115160539A
Application number: CN202211004561.XA
Authority: CN
Inventors: D·弗洛瑟; J·R·海特; L·S·克利; B·埃德姆
Original assignee: Momentive Specialty Chemicals Inc
Current assignee: Hexion Inc
Priority date: 2017-09-12
Filing date: 2018-09-10
Publication date: 2022-10-11
Anticipated expiration: 2038-09-10
Also published as: KR102333935B1; KR20200041985A; PL3697842T3; EP3697842B1; EP3697842A4; CN115160539B; CN111094447B; CN111094447A; BR112020004853A2; BR112020004853B1; BR112020004853A8; WO2019055342A1; US10899873B2; US20190077906A1; EP3697842A1

Abstract

A process for preparing an epoxy resin using an epoxy oligomerization catalyst can be employed, the process comprising mixing a first epoxy resin having a first epoxy equivalent weight of from about 100 to about 600 with a bisphenol compound and a catalyst, thereby forming a second epoxy resin having a second epoxy equivalent weight of from about 200 to about 10,000; wherein the catalyst is a guanidinium catalyst. The second equivalent is greater than the first equivalent.

Description

Process for preparing epoxy resin

The application is a divisional application based on Chinese patent application with the application number of 201880058513.4, the application date of 2018, 9 and 10 months and the invention name of 'process for preparing epoxy resin'.

Background

Technical Field

The present invention relates to epoxy resins. The invention particularly relates to epoxy resins prepared using a guanidinium catalyst.

Background

Historically, epoxy resins have been manufactured using many different catalysts. Exemplary catalysts include: naOH, KOH, triethanolamine, triphenylphosphine, ethyltriphenylphosphonium acetate (ETPPAAc) and ethylphenylphosphonium iodide (ETPPI).

These and other commercially used catalysts, while widely and routinely used, are not without problems. In the field of preparing epoxy resins, it is desirable to prepare them with catalysts that are economical and not sensitive to water. In this field, it is desirable that the catalyst does not introduce compounds that are undesirable for the environment.

Disclosure of Invention

In one aspect, the present invention is a method of making an epoxy resin, the method comprising: mixing a first epoxy resin having a first epoxy equivalent weight of about 100 to about 600 with a bisphenol compound and a catalyst to form a second epoxy resin having a second epoxy equivalent weight of about 200 to about 10,000; wherein the catalyst is a guanidinium catalyst. The second equivalent is greater than the first equivalent. In some embodiments, the guanidinium catalyst has the general formula:

wherein each R is ^1-6 The same or different, can be selected from hydrogen, methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butylButyl, phenyl, benzyl, cyclohexyl, alkylated benzyl, and halogenated benzyl, and X is selected from the group consisting of chloride, bromide, iodide, fluoride, tert-butoxide, n-butoxide, iso-butoxide, tosylate, acetate, methoxide, ethoxide, hydroxide, and combinations thereof.

In another aspect, the present invention is an epoxy resin prepared in a process for making an epoxy resin, the process comprising: mixing a first epoxy resin having a first epoxy equivalent weight of about 100 to about 600 with a bisphenol compound and a catalyst to form a second epoxy resin having a second epoxy equivalent weight of about 200 to about 10,000; wherein the catalyst is a guanidinium catalyst. The second equivalent weight is greater than the first equivalent weight. In some embodiments, the guanidinium catalyst has the general formula:

wherein each R is ^1-6 The same or different, may be selected from the group consisting of hydrogen, methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butyl, phenyl and benzyl, and X is selected from the group consisting of chloride, bromide, iodide, fluoride, tert-butoxide, n-butoxide, iso-butoxide, tosylate, acetate, methoxide, ethoxide, hydroxide and combinations thereof.

In yet another aspect, the present invention is an article of manufacture made using an epoxy resin made in a process for making an epoxy resin, the process comprising: mixing a first epoxy resin having a first epoxy equivalent weight of about 100 to about 600 with a bisphenol compound, a catalyst, and an optional solvent, thereby forming a second epoxy resin having a second epoxy equivalent weight of about 200 to about 10,000; wherein the catalyst is a guanidinium catalyst. The second equivalent is greater than the first equivalent. In some embodiments, the guanidinium catalyst has the general formula:

Embodiments of the invention include:

1) A method of making an epoxy resin, the method comprising:

mixing the following:

a first epoxy resin having a first epoxy equivalent weight of about 100 to about 600,

a bisphenol compound and a bisphenol compound, wherein the bisphenol compound,

a catalyst; and

forming a second epoxy resin having a second epoxy equivalent weight of about 200 to about 10,000;

wherein the catalyst is a guanidinium catalyst and the second epoxy equivalent is greater than the first epoxy equivalent.

2) The process of embodiment 1, wherein the guanidinium catalyst has the general formula:

wherein each R ^1-6 Independently selected from the group consisting of hydrogen, methyl, ethyl, propyl, butyl, isopropyl, isobutyl, t-butyl, phenyl, and benzyl, and X is selected from the group consisting of halide, alkoxide, organic acid anion, hydroxide, and combinations thereof.

3) The method of embodiment 2, wherein X is selected from the group consisting of chloride, bromide, iodide, fluoride, tert-butoxide, n-butoxide, iso-butoxide, tosylate, acetate, methoxide, ethoxide, and combinations thereof.

4) The process of embodiment 1 wherein the second epoxy resin has a second epoxy equivalent weight of about 600 to about 3500.

5) The method of embodiment 2, wherein R ^1-6 Identical and is ethyl.

6) The method of embodiment 2, wherein R ^1-6 Identical and is n-butyl.

7) The process according to embodiment 1, wherein the guanidinium catalyst is present at a concentration of about 0.004 to about 0.070 weight percent, based on the weight of the first epoxy resin and the bisphenol.

8) The process according to embodiment 9, wherein the guanidinium catalyst is present in a concentration of about 0.025 to about 0.050 weight percent based on the weight of the first epoxy resin and the bisphenol.

9) The method of embodiment 1, further comprising using an optional solvent with the first epoxy resin, the bisphenol, or both.

10 The method according to embodiment 9, wherein the solvent is selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, and combinations thereof.

11 An epoxy resin prepared by the process according to embodiment 2 having an epoxy equivalent weight of about 200 to about 10,000.

12 Manufactured goods prepared using the epoxy resin according to embodiment 11.

13 Manufactured article according to embodiment 12, wherein the manufactured article is a composite prepared using an infusion resin that is an epoxy resin according to embodiment 7.

14 Manufactured goods according to embodiment 12, wherein the manufactured goods are paints, coatings, or adhesives.

Drawings

For a detailed understanding of the present application, reference should be made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings set forth below:

FIG. 1 is a graph showing the room temperature stability of the products made during example 1;

FIG. 2 is a graph showing the high temperature stability of the products made during example 1;

FIG. 3 is a graph showing the room temperature stability of the products made during example 2;

FIG. 4 is a graph showing the high temperature stability of the product made during example 2;

FIG. 5 is a graph of the room temperature stability of the products made during example 3, where stability is determined as a function of epoxy equivalent weight over time;

FIG. 6 is a graph of the room temperature stability of the products made during example 3, where stability is determined as a function of viscosity over time;

FIG. 7 is a graph showing the room temperature stability of the products made during example 4; and

fig. 8 is a graph showing the high temperature stability of the products made during example 4.

Detailed Description

One embodiment of the present invention is a method of making an epoxy resin, the method comprising: mixing a first epoxy resin having a first epoxy equivalent weight of about 100 to about 600 with a bisphenol compound and a catalyst to form a second epoxy resin having a second epoxy equivalent weight of about 200 to about 3500; wherein the catalyst is a guanidinium catalyst. The second equivalent is greater than the first equivalent. In some embodiments, the guanidinium catalyst has the general formula:

wherein each R is ^1-6 Identical or different, and can be chosen from hydrogen, methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butyl, phenyl and benzyl. The catalyst can function effectively as an oligomerization catalyst when the first epoxy resin is combined or fused with the bisphenol compound to achieve the desired epoxy equivalent weight. The catalyst itself does not function to cure or crosslink the epoxy resin.

The guanidinium catalysts of the present application are desirably used in a concentration of about 0.004 to about 0.070 weight percent, based on the weight of the first epoxy resin and the bisphenol compound. In some embodiments, the concentration of the catalyst may be from about 0.010 to about 0.060 wt%. In other embodiments, the concentration of the catalyst may be from about 0.025 to about 0.050 weight percent.

Although in most cases the bisphenol compound has only two hydroxyl functions, for the purposes of the present application, the bisphenol compound is a polyphenol compound having two or more hydroxyl functions.

The epoxy resins of the present invention include a liquid epoxy resin component. Epoxy resins are those compounds which contain at least one vicinal epoxy group. The epoxy resin may be saturated or unsaturated, non-aromatic, aromatic or heterocyclic, and may be substituted. Liquid epoxy resins are defined as epoxy resins having a viscosity of less than 100Pa-s at 25 ℃. The liquid epoxy resin may also be monomeric or polymeric. The liquid epoxy resin component constitutes from about 45 weight percent (wt.%) to about 98.5wt.%, such as from about 60wt.% to about 98.5wt.%, of the epoxy resin system.

In one embodiment, the first epoxy resin component may be prepared by reacting an epihalohydrin, such as epichlorohydrin, with a compound containing at least one, two or more hydroxyl groups under basic conditions, such as in an alkaline reaction medium or in the presence of a suitable base.

Examples of such suitable liquid epoxy resins include, but are not limited to, polyglycidyl ethers of polyhydric or dihydric phenols, polyglycidyl ethers of glycols or polyglycols, epoxy varnish resins, other glycidated polyphenol resins, polyglycol esters of polycarboxylic acids, fused reaction products between epoxy resins and additional polyhydric phenolic compounds as disclosed and described in U.S. Pat. nos. 3,477,990 and 4,734,468, which are incorporated herein by reference in their entirety.

Examples of suitable bisphenol compounds for preparing liquid epoxy resins include, but are not limited to, resorcinol, catechol, t-butyl catechol, hydroquinone, bisphenol A (BPA), bisphenol E (BPE), bisphenol F (BPF), tris (4-hydroxyphenyl) methane, 1-bis (4-hydroxyphenyl) isobutane, 2-bis (4-hydroxyphenyl) butane, 2-bis (4-hydroxy-3-t-butylphenyl) propane, 1-bis (4-hydroxyphenyl) cyclohexane, 2,6,2',6' -tetrachloro-p, p ' -bisphenol A, 2,6,2',6' -tetrabromo-p, p ' -bisphenol A, 2,6,2',6' -tetramethyl-3, 5,3' -tetrabromo-p, p ' -bisphenol, 2,6,2',6' -tetramethyl-3, 5,3',5' -tetrabromo-p, p ' -bisphenol, tetramethylbisphenol, 1, 5-dihydroxynaphthalene, bis (2-hydroxy-1-naphthyl) methane, bis (4-hydroxyphenyl) sulfone, and the like, and combinations thereof. Preferred epoxy resins are aromatic or non-aromatic epoxy resins based on bisphenol a, bisphenol F, phenolic novolac resins, hydrogenated bisphenol a, non-aromatic diols, or combinations thereof.

Commercial examples of suitable liquid epoxy resins include, but are not limited to, EPON, commercially available from Hexion inc ^TM Resins 825, 826, 828, 860, and 862.

In another embodiment, the liquid epoxy resin component may contain a monofunctional or multifunctional epoxy diluent as a viscosity reducing agent. Suitable diluents include monoglycidyl ethers of alcohols, or polyglycidyl ethers of non-aromatic diols or triols or polyols, or polyglycols. The additive may be a monofunctional epoxy additive, which may also include a monoglycidyl ester.

In another embodiment, the liquid epoxy resin component optionally includes an acrylate material, such as an acrylate monomer containing one or more reactive acrylate double bonds. Unless specifically described otherwise herein, acrylate monomers refer to acrylates or acrylates. In one implementation of the invention, the acrylate monomer may be an acrylate or a combination of acrylate monomers. Suitable acrylate monomers include acrylates of mono-or polyols, methacrylates of mono-or polyols, or combinations thereof. Alternatively, the acrylate material may be a polyacrylate or polymethacrylate of a polyol that contains more than one capped acrylate or methacrylate group. Preferred esters are acrylic and methacrylic esters of non-aromatic polyols, for example di-and polymethacrylates of alkylene glycols, alkyleneoxy glycols, cycloaliphatic glycols and higher alcohols, such as ethylene glycol, triethylene glycol, tetraethylene glycol, tetramethylglycol, hexanediol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol and the like, or mixtures of these esters with each other or their partially esterified analogs. Other preferred esters include monoacrylates or monomethacrylates of alcohols or polyols.

Suitable acrylate materials are acrylates or methacrylates of polyols including, but not limited to, trimethylolpropane triacrylate, trimethylolethane triacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, neopentyl glycol diacrylate, tetramethylene glycol dimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, 1, 6-hexanediol diacrylate, 1, 6-hexanediol dimethacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and combinations thereof. Particularly preferred acrylates or methacrylates of polyols are trimethylolpropane triacrylate, pentaerythritol tetraacrylate, neopentyl glycol diacrylate and combinations thereof. The acrylate or methacrylate ester of the additional polyol is an acrylate or methacrylate ester of an epoxide resin, wherein the epoxide resin as used herein is considered a polyol.

When present in the liquid epoxy resin component, an optional acrylate material, such as an acrylate of a mono-or polyol, a methacrylate of a mono-or polyol, or a combination thereof, may be mixed with from about 1 weight percent (wt.%) to about 50wt.%, such as from about 5wt.% to about 40wt.%, of the epoxy resin component, for example from about 10wt.% to about 40wt.%, or from about 20wt.% to about 40wt.% of the liquid epoxy resin component.

The epoxy resin system may comprise a non-aromatic polyol compound. The non-aromatic polyol compound may include a diol having a number average molecular weight of about 1000 to 10000 (daltons).

Examples of suitable diols include poly (ethylene oxide) diol, poly (propylene oxide) diol, poly (butylene oxide) diol, polytetrafluoro furan diol, poly (ethylene adipate) diol, poly (propylene sebacate) diol, poly (hexamethylene carbonate) diol, silicone-alkylene oxide copolymers, poly (butadiene)-co-acrylonitrile) glycols and combinations thereof. An example of a silicone-alkylene oxide copolymer is SILWET ^TM L-7230 copolymer.

The determination of the epoxy equivalent weight for the process of the present application can be carried out in any manner known to be useful to the person skilled in the art. For example, ASTM D1652 can be used. In this method, the epoxy equivalent is determined by titration with a perchloric acid solution in glacial acetic acid.

Bisphenols for use herein include, but are not limited to, bisphenols such as bisphenol a, bisphenol F, bisphenol S, and bisphenol AD. Multifunctional bisphenols such as urethane and isocyanate modified epoxy resins or bisphenol a and their halogen or alkyl substituted analogs may also be used. Hydrogenated versions of any of these compounds may also be used. Any bisphenol known to those skilled in the art that can be used to oligomerize the first epoxy resin to a higher epoxy equivalent weight can be used in the process of the present application.

Since the catalyst used in the process of the present application is not sensitive to water, a variety of solvents can be used in the process of the present application. These include aqueous solvents, which include water itself. Organic solvents that may be used in the present application include those known to be useful in epoxy resin synthesis reactions. Particularly desirable are water-soluble organic solvents such as methyl ethyl ketone, methyl isobutyl ketone, and the like.

Non-polar solvents may also be used. For example, toluene, xylene, and other non-polar solvents may be used in the process of the present application.

The starting or first resin useful in the process of the present application has an epoxy equivalent weight of from about 100 to about 600. They are then desirably oligomerized to an epoxy equivalent weight of from about 200 to about 10,000. In other embodiments, the epoxy resin has a final epoxy equivalent weight of about 600 to about 3500. In other embodiments, the final epoxy equivalent weight is from about 1100 to about 1800.

Catalysts useful in the process of the present application have the general formula:

wherein each R is ^1-6 Identical or different, and can be chosen from hydrogen, methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butyl, phenyl and benzyl. In some embodiments, each R is ^1-6 Identical, and is ethyl. In other embodiments, they are the same and are propyl. In other embodiments, each R is ^1-6 Independently selected from methyl, ethyl and propyl.

In the formula, X may be a halogen ion. In some embodiments, the halide is desirably chloride, although other halides may also be used. In most embodiments of the methods of the present application, the halide ion will be selected from chloride, bromide, and iodide. In less cases, the halide will be fluoride.

Alternatively, X may also be a member selected from the group consisting of tert-butoxide, n-butoxide, iso-butoxide, tosylate, acetate, methoxide, ethoxide, hydroxide, and combinations thereof.

The catalysts claimed in this application are believed to have many desirable properties. They are believed to have higher activity than conventional catalysts. For example, hexaethylguanidinium chloride (where all R in the formula are R) is used in contrast to an otherwise equivalent experiment using triphenylphosphonium iodide ^1-6 Ethyl) produces an epoxy resin with less residual bisphenol a.

While not wishing to be bound by any theory, it is believed that both the higher activity and the observed thermal stability of the catalysts claimed in this application are due to the presence of resonant structures. For example, hexaethylguanidinium chloride has a resonance structure of 4 equivalents (chloride ion not shown):

by being able to so easily delocalize the positive charge, it is believed that this resonance results in chloride ions being less tightly bound or more "free" than the anions of some other catalysts. This resonance also contributes to thermal stability, as the positive charge delocalizes making the catalyst less susceptible to Hoffman degradation (Hoffman interactions).

For example, hexaethylguanidinium chloride was observed to be fairly stable to water and free of known neurotoxicity or other extreme health hazards. It is believed that other hexaethylguanidinium chloride salts will have similar properties.

The oligomerization or fusion reaction of the methods of the present application can be carried out using any conditions known to those skilled in the art to be useful for preparing epoxy resins.

Epoxy resins prepared according to the methods of the present application can be used as infusion resins and composites. They can also be used in paints, coatings and in the manufacture of adhesives. In general, where conventional resins having the same or similar physical properties can be used, resins prepared according to the methods of the present application can be used.

Examples

The following examples are provided to illustrate aspects of the invention. The examples are not intended to limit the scope of the invention and should not be so interpreted. Amounts are in parts by weight or% by weight unless otherwise indicated.

Terms and abbreviations

Epoxy Equivalent Weight (EEW).

Hexaethylguanidinium chloride (HEGCl), a catalyst.

Ethyl phenyl phosphonium iodide (quaternary phosphonium iodide (ETPPI), a control catalyst.

Bisphenol a (BPA), a phenolic compound.

Propylene Glycol Methyl Ether (PGME), a solvent.

Resin per epoxy (WPE) is another term for epoxy equivalent.

Dodecylbenzene sulfonic acid (DDBSA), a surfactant.

Triphenylphosphine (TPP), a control catalyst.

Example 1-procedure using HEGCl in the preparation of Experimental epoxy resin 1

Experiment of

The liquid epoxy resin A is a diglycidyl ether grade bisphenol A, has an epoxy equivalent of 185 to 192 and a viscosity of 11 to 15Pa-s at 25 ℃, and is sold by Hexion Inc.

Liquid epoxy resin A (0.5733 lbs, 260 grams (g)) was charged to a degassed reaction vessel. BPA (0.1767 lbs, 80.2 g) was charged and the kettle was heated to 150-250F (65-121℃).

HEGCl (0.00042 lbs, 0.2 g) was charged at this temperature and the reaction exotherm was allowed to reach 385 ° F (196 ℃).

Xylene (0.25 lbs, 113.4 g) was charged and the product was cooled to 100-130F (37.7-54.4 deg.C) over 30-60 minutes with stirring. The resin was then recovered for testing.

The initial epoxy equivalent weight of the resin was about 190. The product resins were tested for epoxy equivalent, percent non-volatiles, gardner viscosity, gardner color and amount of free bisphenol A. The results are shown in table 1 below. Changes have been made as shown in the table and are recorded as follows.

TABLE 1 HEGCl was used in the preparation of Experimental epoxy resin 1

* The percentage value is the amount of catalyst added as a percentage of the amount of ETPPI known to be effective

* Based on the total weight of BPA + resin

Discussion of the preferred embodiments

The results of table 1 should be read in conjunction with figures 1 and 2. Figures 1 and 2 show that epoxy resins made using the claimed novel catalyst have equivalent stability to resins made using conventional catalysts.

Two control or comparative experiments were performed using ETPPI as a catalyst. These results clearly show that HEGCl is significantly more effective or active in building epoxy equivalents and reducing residual free bisphenol a in the resin. As shown, HEGCl is at the same level as ETPPI, resulting in higher epoxy equivalent weight (521 vs 492). However, for HEGCl, almost the same amount of epoxy equivalent (511 and 503) is generated when half the level is used, even only 10% of the ETTPI. It should be further noted that the active iodide ion for ETTPI was about 29% by weight of the catalyst, while the corresponding active chloride ion in HEGCl was only about 12% by weight of the catalyst, thus indicating that the effect of HEGCl was even more profound than immediately apparent. In this epoxy fusion reaction, HEGCl showed more than 10 times the activity of ETTPI.

Looking again at the free BPA results, ETTPI at 100% produced a resin with a free BPA level of less than 40 ppm. In contrast, HEGCl produced no measurable free BPA in the 10-100% range of the comparison, using a test with a sensitivity of 40 ppm. In view of the test sensitivity, in the following experiments, a control producing >40ppm BPA was used to confirm the effect on BPA levels.

This experiment shows that the activity of the claimed catalyst HEGCl is about 5 to about 10 times higher than the conventional catalyst ETPPI. Even at a concentration of only 5%, it is capable of forming a large amount of EEW structures during the formation reaction, compared to conventional catalysts.

Example 2-procedure using HEGCl in the preparation of Experimental resin 2

Experiment of the invention

Example 2 was prepared essentially the same as example 1 except 0.2597 lbs (118 g) of liquid epoxy resin a; BPA was used in an amount of 0.1401 lbs (63.5 g); using 0.0001-0.0002 lbs (0.045-0.09 g) of HEGCl; 0.1800 lbs (81.6 g) of xylene was used; and 0.4200 lbs (190.5 g) of 2-butoxyethanol was used.

The initial epoxy equivalent weight of the liquid epoxy resin a was about 190. The epoxy equivalent and the amount of free bisphenol A were measured in-process. The product resins were tested for epoxy equivalent, percent non-volatiles, gardner viscosity, gardner color and amount of free bisphenol A. The results are shown in table 2 below.

TABLE 2 HEGCl was used in the preparation of Experimental epoxy resin 2

* Based on the total weight of BPA + resin

Discussion of the related Art

The results of table 2 should be read in conjunction with figures 3 and 4. Figures 3 and 4 show that epoxy resins made using the claimed novel catalyst have comparable stability to resins made using conventional catalysts. In view of all other data points, the drop in the Ex 2B room temperature study in fig. 3 is clearly an outlier, which can be ignored.

A comparative experiment was performed using ETPPI as a catalyst. These results clearly show that HEGCl is significantly more effective or active than ETPPI in building epoxy equivalents and reducing residual free bisphenol a in the resin. This can be seen when comparing the EEW of samples Ex 2 COMP and Ex 2B, using the same weight ratio of catalyst in Ex 2B, but much more EEW structure (2190 compared to 2684). It should be further noted that the active iodide ion for ETTPI was about 29% by weight of the catalyst, while the corresponding active chloride ion in HEGCl was only about 12% by weight of the catalyst, thus indicating that the effect of HEGCl was even more profound than immediately apparent. These experiments showed that HEGCl was more than twice as active as ETTPI.

Again looking at the free BPA results, ETTPI at 100% produced a resin with a free BPA level of 340 ppm. In contrast, at 75% by weight ETTPI loading, HEGCl produced less than 40ppm of free BPA using a test with a sensitivity of 40 ppm.

Example 3-procedure using HEGCl in the preparation of Experimental epoxy resin 3

Experiment of

Example 3 was prepared essentially as in example 1, except that 0.3770 lbs (171 g) of liquid epoxy resin a was used; 0.1165 lbs (53 g) of BPA was used; using 0.0001-0.0002 lbs (0.045-0.09 g) of HEGCl; and 0.0406 lbs (18.4 g) of 2-butoxyethanol was used. Also, 2-butoxyethanol solvent was added at high temperature to aid in cooling the reaction to 235 ° F (113 ℃) after the exotherm. At this point, inversion water (inversion water) was added and the reaction mixture was stirred for 1 hour at 150-220 ℃ F. (65.6-104.4 ℃). The reaction was then cooled to 90-140 ° F (32.2-60 ℃) and mixed under full vacuum. Finally, acetone (0.0053 lbs, 2.4 g), DDBSA (0.0003 lbs, 0.14 g) and liquid epoxy resin B (which is an aliphatic monoglycidyl ether containing an alkyl chain between C12 and C14 in length) (0.0406 lbs, 18.4 g) were added and diluted with water to the final desired solid after mixing.

The initial epoxy equivalent weight of the resin was about 521. The EEW and the conversion temperature during formation of the second resin were measured in-process. The final resin was tested for the properties exhibited. The results, including variations, are shown in table 3 below.

TABLE 3 use of HEGCl in preparation of Experimental epoxy resin 3

	Ex.3	EX.3 COMP
			Catalyst and process for preparing same	HEGCl	TPP
Target loading% catalyst	10％	10％
			In the process:
EEW (in-process)	506	421.6*
			Final properties
％NV	53.2	54.5
			EEW (Final resin)	521.3	449.3*
Viscosity, cps @% NV	2,100(i)	1,780(i)
			Free BPA (ppm)	<40	1,916

* The percentage values are the amount of catalyst added as a percentage of the amount of TPP normally added

Discussion of the related Art

The results of table 3 should be read in conjunction with fig. 5 and 6. Figures 5 and 6 show that epoxy resins made using the claimed novel catalyst have much superior stability compared to resins made using conventional TPP catalysts. The product of this example was tested only at room temperature, but EEW and viscosity stability were tested. The viscosity growth or instability of resins prepared using conventional catalysts is quite significant compared to resins prepared using the claimed catalysts.

Comparative experiments (ex.3 Comp, table 3) were carried out using triphenylphosphine as catalyst. It is noted that only 10% of the normal loading was performed and the claimed catalyst was superior to TPP in both EEW structure and almost complete BPA consumption compared to the residual BPA observed in the comparative example, which was close to 2000 ppm. It should be further noted that the active iodide ion for ETTPI was about 29% by weight of the catalyst, while the corresponding active chloride ion in HEGCl was only about 12% by weight of the catalyst, thus indicating that the effect of HEGCl was even more profound than immediately apparent. These results clearly show that HEGCl is more efficient or more active than TPP in building epoxy equivalents and reducing residual free BPA in the resin, since epoxy build is much higher at equivalent catalyst loadings.

TTP at 10% produced a resin with free BPA of 1916 ppm. In contrast, HEGCl produced less than 40ppm free BPA at the same loading weight using a test with a sensitivity of 40 ppm.

Example 4-procedure using HEGCl in the preparation of Experimental epoxy resin 4

Experiment of

Example 4 was prepared essentially the same as example 1 except 0.3306 pounds (150 g) of liquid epoxy resin A was used, 0.1694 pounds (77 g) of BPA was used, 0.000075 to 0.0003 pounds (0.034 to 0.136 g) of HEGCl was used, 0.375 pounds (170 g) of xylene was used, and 0.125 pounds (56.7 g) of 1-butanol was used.

The liquid epoxy resin had an initial epoxy equivalent weight of about 190. In-process measurements were performed on EEW and free BPA. The final resin was tested for the properties exhibited. The results are shown in Table 4 below.

TABLE 4 use of HEGCl in preparation of Experimental epoxy resin 4

(a) The percentage value is the amount of catalyst added as a percentage of the amount of ETPPI normally added

The results of table 4 should be read in conjunction with fig. 7 and 8. Figures 7 and 8 show that epoxy resins made using the claimed novel catalyst have substantially equivalent stability compared to resins using conventional catalyst textures.

A comparative experiment was performed using ETPPI as a catalyst. These results clearly show that HEGCl is significantly more effective or active in building epoxy equivalents and reducing residual free bisphenol a in the resin. In this experiment, the new catalyst showed at least 5 times the activity by comparing the comparative example with example 4A. Only 18% HEGCl catalyst is able to build almost the same epoxy equivalent as 100% ETPPI catalyst. The comparative and 18% examples also consumed approximately the same amount of BPA. These results clearly show that HEGCl is more efficient or more active than TPP in building epoxy equivalent and reducing free BPA remaining in the resin, since epoxy build is much higher at equivalent catalyst loadings.

Looking again at the free BPA results, ETTPI at 10% produced a resin with a free BPA level of 59 ppm. In contrast, HEGCl produced less than 40ppm free BPA at the same loading weight using a test with a sensitivity of 40 ppm.

Test method

The assays performed in the examples may use any method known to be useful to those skilled in the art. Exemplary methods include, but are not limited to: gardner color ASTM D-1544; viscosity ASTM D445; nonvolatile matter ASTM D2369; epoxy equivalent ASTM D1652-11; and dispersivity by Hageman analysis (D1210-05).

Residual BPA can be determined using ASTM D7574.

Claims

1. A method of making an epoxy resin, the method comprising:

mixing the following:

a first epoxy resin having a first epoxy equivalent weight of 100 to 600,

bisphenols, and

a guanidinium catalyst, wherein the guanidinium catalyst is present in a concentration of 0.004 to 0.070 weight percent based on the weight of the first epoxy resin and the bisphenol; and

forming a second epoxy resin by reacting the mixture to achieve a higher second epoxy equivalent of 200 to 10,000 for the first epoxy equivalent;

wherein the guanidinium catalyst has the general formula:

wherein each R ^1-6 Independently selected from the group consisting of hydrogen, methyl, ethyl, propyl, n-butyl, isopropyl, isobutyl, t-butyl, phenyl, and benzyl, and X is an anion selected from the group consisting of halide, alkoxide, organic acid anion, hydroxide, and combinations thereof.

2. The method of claim 1, wherein X is selected from the group consisting of chloride, bromide, iodide, fluoride, tert-butoxide, n-butoxide, iso-butoxide, tosylate, acetate, methoxide, ethoxide, and combinations thereof.

3. The method of claim 1, wherein the second epoxy resin has a second epoxy equivalent weight of 600 to 3500.

4. The method of claim 1, wherein R ¹ -R ⁶ Identical and is ethyl.

5. The method of claim 1, wherein R ¹ -R ⁶ Identical and is n-butyl.

6. The process according to claim 1, wherein the guanidinium catalyst is present in a concentration of 0.025 to 0.050 weight percent based on the weight of the first epoxy resin and the bisphenol.

7. The method of claim 1, further comprising using an optional solvent with the first epoxy resin, the bisphenol, or both.

8. The method according to claim 7, wherein the solvent is selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, and combinations thereof.

9. The method of claim 1, wherein the bisphenol compound comprises bisphenol a.

10. The method of claim 1, wherein the bisphenol compound comprises bisphenol a, and the second epoxy resin has less than 40 parts per million (ppm) residual free bisphenol a.

11. An epoxy resin prepared by the process of claim 1 having an epoxy equivalent weight of 200 to 10,000.

12. Manufactured articles prepared using the epoxy resin according to claim 11.

13. The article of manufacture of claim 12, wherein the article of manufacture is a composite material.

14. The article of manufacture of claim 12, wherein the article of manufacture is a paint, coating, or adhesive.